Downloading plugins

Hi everyone,
I purchased the optibox evo e3hd recently, and I must say I'm pretty new with Enigma 2...
I try to download plugins from the plugin menu, but I receive a 'http error'
I am able to download plugins from the software managment menu (advanced options-> packet management), but even thought they get correctly installed they don't appear in the plugins menu list
Am I doing something wrong? Do i need to change some settting?